The present disclosure relates in general to computer systems and in particular to reducing the current demand of a computer system during its startup.
Computer systems are information handling electronic systems which can be designed to give independent computing power to one user or a plurality of users. Computer systems may be found in many forms including, for example, mainframes, minicomputers, workstations, servers, personal computers, internet terminals, notebooks, and embedded systems. Computer systems include desk top, floor standing, rack mounted, or portable versions. A typical computer system includes at least one system processor, associated memory and control logic, and peripheral devices that provide input and output for the system. Such peripheral devices may include display monitors, keyboards, mouse-type input devices, floppy and hard disk drives, CD-ROM drives, printers, network capability card circuits, terminal devices, modems, televisions, sound devices, voice recognition devices, electronic pen devices, and mass storage devices such as tape drives, CD-R drives, or DVDs.
During the startup of a computer system such as during the initial powering up of a computer system, computer components such as system memory modules can draw a relatively large amount of current during the time that they become operational. For example, some memory modules include multiple DRAM chips that require a relatively large current draw to charge the memory cells of the DRAM circuits. Some existing memory modules may draw up to 5 amps during the initial charging of the memory cells. Future modules may draw more. Because a computer system may include a relatively large number of system memory modules (e.g., 32), the momentary current demand of the computer system during startup may exceed the capacity of the computer system""s power supply.
To compensate for the large current demand during startup, a computer system may be outfitted with a larger power supply. However, providing a computer system with a larger power supply can increase the cost of a computer system as well as reduce the available space for other components in a computer system chassis. Such an option is not feasible with some computer systems such as a portable computer system. Also, some computer systems are safety rated based upon the size of their power supply. Consequently, providing a computer system with a larger power supply may also provide the computer system with an undesirably higher safety rating, thereby restricting the sale of the computer system to a limited number of consumers. Furthermore, some large capacity power supplies do not operate efficiently at low current conditions. Consequently, sizing a power supply to meet a large current demand during startup may provide a computer system with a power supply that operates inefficiently during the normal operation of the computer system.
What is desirable is to reduce the current demand of a computer system during the startup of the computer system.
It has been discovered that staggering the startup current draw of a plurality of computer components advantageously reduces the current demand of a computer system during startup.
In one aspect of the embodiments of the present disclosure, a computer system includes a plurality of computer components and a clock circuit having a plurality of outputs. Each of the plurality of outputs is coupled to at least one of the plurality of computer components to provide a clock signal at a normal operating frequency in a stagerred progression with the outputs of the plurality of outputs during a startup of the computer system.
In another aspect, the present embodiment includes a method for making operational a plurality of computer components during the startup of a computer system. The method includes providing a first clock signal at a normal operating frequency to a first computer component. The method also includes providing, after the providing of the first clock signal, a second clock signal at a normal operating frequency to a second computer component.
In yet another aspect of the embodiments of the present disclosure, a computer system includes at least one system processor and a system memory operably coupled to the at least one system processor. The system memory includes a plurality of memory modules. The computer system also includes means for staggering an initial charging current draw of the plurality of memory modules during a startup of the computer system.